Topic       : The GFA-Basic Compendium
Author      : GFA Systemtechnik GmbH
Version     : GFABasic.HYP v2.98 (12/31/2023)
Subject     : Documentation/Programming
Nodes       : 899
Index Size  : 28056
HCP-Version : 3
Compiled on : Atari
@charset    : atarist
@lang       : 
@default    : Document not found
@help       : Help
@options    : +g -i -s +z
@width      : 75
@hostname   : STRNGSRV
@hostname   : CAB     
@hostname   : HIGHWIRE
@hostname   : THING   
View Ref-FilePLOT x,y
LINE x1,y1,x2,y2
DRAW [TO][x,y]
DRAW [x1,y1][TO x2,y2][TO x3,y3][TO...]

x, y, x1, y1, x2, y2, x3, y3: iexp

PLOT draws a point with the coordinates x,y on the screen. LINE draws a line
between the coordinate pairs x1,y1 and x2,y2. The style and color of this line
can be defined by means of the commands DEFLINE and COLOR.

DRAW x,y corresponds to the command PLOT. By means of DRAW TO x,y, a line is
drawn between the coordinates x,y and the last set point, regardless of whether
this point was set by PLOT, LINE, or DRAW.

A further variant of the command, DRAW x1,y1 TO x2,y2 corresponds to the LINE
command, and addionally with this command, further coordinates can be specified
allowing shapes such as polygons to be produced. This latter variant of the
command makes it possible to create structures which are similar to the
turtle-graphic commands of Logo and the Hewlett-Packard standard plotter
language, HPGL. In this way, it is possible to simulate a plotter on the
screen.

Examples:

    x=50
    y=50
    LET color=POINT(x,y)
    PRINT color
    PLOT x,2*50
    LINE 200,200,400,100
    PRINT POINT(x,100)

--> The program examines the color of the point 50,50 and prints this out on
    the screen. It then plots a second point, plots a line and reports on the
    color of the second point plotted.

    DO
      MOUSE mx,my,mk
      IF mk=1
        DRAW  TO mx,my
      ENDIF
      EXIT IF mk=2
    LOOP

--> When the left mouse key is pressed a line is drawn between the last set
    point and the absolute coordinates mx,my. The loop is terminated by
    pressing the right mouse button.

v_pline()+